1. The Field of the Invention
The present invention relates to an apparatus for cooling fluids. More particularly, the present invention relates to an in-line thermoelectrically operated water-cooling device formed as a single-ended cylindrical cartridge vertically mounted on a flowboard.
2. The Prior Art
The present invention pertains to methods and systems for water conditioning, treatment and purification and, in particular, to domestic units which are readily adaptable to treat local water in accordance with any existing long term or varying temporary condition to produce water of high purity and to a flowboard for controlling fluid distribution in the system.
Impurities in natural raw waters (surface or well water) occur in four basic different forms, namely non-ionic and undissolved impurities; ionic and dissolved impurities; gaseous impurities; and biological impurities. Each of these impurities requires separate treatment techniques and equipment for their removal.
Non-ionic and undissolved impurities include, but are not Limited to, turbidity, silt, mud, suspended solids, organic matter, bacteria, oil colloidal matter and colloidal silica.
Ionic and dissolved impurities include: a wide variety of salts dissolved in water and dissociated to form positive ions, called cations, and negative ions, called anions. The major cations in natural raw water are calcium, magnesium sodium, potassium, ammonium, iron and manganese. The major anions are carbonate, bicarbonate, hydroxide, chloride, sulfate, nitrate, phosphate, and silica.
Gaseous impurities include a number of gases that are soluble in water. Some are found naturally in well water, such as carbon dioxide, hydrogen sulfide, and methane. Others are the result of water purification or industrial application and include such gases as ammonia, oxygen and chlorine.
Biological impurities include all types of microorganisms, bacteria, viruses, and pyrogen.
In most cases, all of these four forms of impurities coexist simultaneously and in differing amounts and their relative proportions can vary, even seasonally. No single treatment or technique is adequate for or capable of removing all impurities in one step. Multiple related or interdependent processes are normally required to rid water from such impurities. Generally these processes must be constantly monitored to assure each form of impurity is being properly treated and removed.
The inventor of the subject invention is also the inventor of U.S. Pat. Nos. 6,080,313 and 6,099,735, the disclosures of which are incorporated herein by way of reference. These patents describe counter-top modular water purification and disinfection systems to remove water impurities and produce water of high quality and purity as presented in the forgoing introduction. All water treatment and control modules are single ended, bottle-like cartridges of different functions mounted on a uniquely designed flow circuit forming a base, which was named xe2x80x9cflowboard.xe2x80x9d The subject invention discloses the use of a water cooler in the form of a bottle-like cartridge to be mounted on a flowboard of a stand-alone water-cooling apparatus or as a cooling module in a water purification system of the type described in the aforementioned patents. The flowboard is a flat box-like assembly concealing a fluid conduit extending between an inlet and an outlet and a plurality of mounting receptacles connected to the conduit, each receptacle receiving a single ended cartridge or a module vertically therein, whereby water is purified and cooled while passing from the inlet to be dispensed at the outlet. Prior art in thermoelectric fluid cooling, for example, U.S. Pat. Nos. 4,384,512 to Keith; 4,752,389 to Burrows; 4,913,318 to Forrester; 5,209,069 to Newman; 5,501,077 to Davis et al; and 5,544,489 to Moren describe the use of conventional thermoelectric cooling devices as affixed to the surface of a water container for the purpose of cooling water by natural convection within the container. U.S. Pat. No. 4,281,516 to Berthet et al describes a thermoelectric cooling device comprising a liquid flow circuit in the form of a bendable metal tube imbedded within the cold plate of a multi-plate thermoelectric cooler system. U.S. Pat. No. 5,494,195 to Knuettel et al describes a thermoelectrically cooled beverage dispenser comprising a liquid flow circuit in the form of a channel having affixed conventional thermoelectric devices.
None of the prior art devices depicts an in-line, fully integrated, single element fluid cooling system in the form of a detachable bottle-like coaxial cylindrical cartridge, having only one port for fluid inlet and outlet, and is easily mounted on or removed from a flowboard or a manifold without tools and without disturbing the piping, wiring or other parts of the apparatus.
It is therefore an object of the present invention to provide a fully functional single-element thermoelectric water cooling device in the form of a vertically mounted cylindrical cartridge, which is similar to those used for water filtration and purification.
It is another object of the present invention to provide a cooling cartridge that provides immediate, on-demand cold water without requiring a reservoir for storing cold water.
It is another object of the present invention to provide a water-cooling cartridge, which is easy to install or to replace without the need for any tools or equipment.
It is another object of the present invention to provide a water-cooling cartridge, which has a single end with a water inlet and a water outlet forming a single concentric port.
It is a further object of the present invention to provide a water-cooling cartridge that can be mounted on a flowboard so as to be included with various other elements for water treatment.
It is a further object of the present invention to provide one or more water-cooling cartridges that can be mounted on a flowboard for a stand-alone counter top water cooler.
It is still a further object of the present invention to provide one or more water-cooling cartridges that can be mounted on a linear flowboard in the form of a manifold.
It is another object of the present invention to provide a water-cooling cartridge whereby the water flows upwardly through an annulus of a chamber and leaves axially through the water outlet tube.
It is another object of the present invention to provide a water-cooling cartridge whereby the water flows upwardly through a single entry circumferential helix disposed on an internal compartment, forming a narrow annulus with the water pipe, for the purpose of enhancing flow velocity and subsequently heat transfer rate.
It is a further object of the present invention to provide a water-cooling cartridge whereby the water flow pipe has external flat surfaces preferably of equal size so as to form a square wall pipe having a square internal channel.
It is a further object of the present invention to provide a water-cooling cartridge whereby the water flow pipe is a rectangular block with external flat surfaces of equal sides so as to form a square wall pipe having drilled or cast therein a circular internal passageway.
It is a further object of the present invention to provide a water-cooling cartridge whereby the water flow pipe is a conventional cylindrical pipe having affixed blocks of external flat surfaces and internal contoured surfaces for mating the pipes.
It is another object of the present invention to provide a water-cooling cartridge that can include a multi-section finned heat sink affixed circumferentially around the water flow pipe in which the heat sink is separated from the external surface of the water flow pipe by an insulating material.
It is another object of the present invention to provide a water-cooling cartridge having a multi-section finned heat sink which is formed of an economical highly heat conductive material such as aluminum.
It is another object of the present invention to provide a water-cooling cartridge in which the finned member of the heat sink has extruded, machined or molded longitudinal fins of different lengths which extend along the length of the heat sink with each heat sink affixed to one side of the water flow pipe external wall so as to form a continuous circular heat exchanging surface.
It is still another object of the present invention to provide a water-cooling cartridge which employs one or more thermoelectric elements positioned between the surface of the water flow pipe and the heat sink so as to circumferentiary surround the water flow pipe.
It is another object of the present invention to provide a water-cooling cartridge which has the heat sink positioned within an external shell and provided with an integrated forced convection means, such as an electrically operated fan.
It is another object of the present invention to provide a water cooling cartridge whereby the fan is placed at the top of the cartridge so as to induce atmospheric air through an opening of the bottom of the shell in a coaxial flow pattern parallel to the hot sink finned members so as to cool the hot sink and to enhance heat transfer across the cartridge.
It is another object of the present invention to provide a water-cooling cartridge which has no exposed piping, piping connections or electrical wiring.
It is another object of the present invention to provide a water-cooling cartridge, which is temperature controlled with an integrated thermostat.
It is still a further object of the present invention to provide a water-cooling cartridge that can meet the infrequent or continuous variable demand of cold water by the use of a single cartridge having adequate diameter, height, internal heat transfer enhancing means such as a helix, and number of thermoelectric devices, or by a series of standard size water-cooling cartridges of the type described herein.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.
The present invention is an apparatus for cooling and dispensing fluids having a flowboard with a fluid passageway extending between an inlet and an outlet, and a water-cooling cartridge removably fixed to a mounting block or receptacle within the flowboard connected to the passageway. The water-cooling cartridge has a coaxial inlet and outlet for communicating with the fluid passageway of the flowboard. The water-cooling cartridge has: a square water flow pipe acting as a cold junction or cold plate and communicating with the inlet of the water-cooling cartridge; a finned heat sink positioned around the water flow pipe and separated therefrom with insulating material; a thermoelectric device acting as a heat pump securely positioned between the heat sink and the water flow pipe; a shell enclosing the heat sink defining a coaxial passageway for induced cooling air flow and forming an external housing for the water-cooling cartridge; a fin mounted at the top of the water-cooling cartridge so as to draw or induce air flow along the heat sink; and a thermostatic device for controlling water temperature above its freezing point.
The water outlet tube is axially placed in the water flow pipe and communicates with the outlet of the water-cooling cartridge. The interior wall of the water flow pipe for low capacity cooling defines an annulus with an exterior surface of the outlet axial tube and communicates with the inlet of the water-cooling cartridge. For high capacity water cooling, the interior of the water flow pipe is slightly tapered and houses a relatively large diameter cylindrical compartment, forming a narrow annulus with the water flow pipe. The compartment has a single inlet circumferential helical channel disposed on its external surface in close proximity to the water flow pipe so as to form a continuous single passageway for water flow.
The water flow pipe preferably has flat external surfaces defining a square internal channel or forming a cylindrical channel within a rectangular metal block. The water flow pipe acts as a cold junction or cold plate (cold side), where heat is absorbed from the fluid mostly by convection. It is preferable to maintain the cold plate temperature at about 35xc2x0 F. (as determined by the design of the thermoelectric devices and process requirements). Lower temperatures should be avoided to prevent water freezing and subsequent blocking of water flow. Heat transfer between solids and liquids is relatively higher than between solids and air. Therefore, the heat sink (hot side), where heat is rejected, is normally large with multiple protrusions or fins to increase the exposed surface. However, in another embodiment of the water flow pipe, internal longitudinal fins or means to induce turbulence could be provided to enhance heat transfer through the liquid. A unique design of such heat transfer enhancement means is described hereafter. The thermoelectric devices are affixed to at least one of these external flat surfaces. The water flow pipe, with its flat external surfaces, is preferably made of high conductive metal hygienically acceptable for potable water service (such as copper or aluminum with an inert surface coating). The heat sink preferably has four sections, which are affixed circumferentiary to the fill length of the external wall of the water flow pipe. The cross section of each heat sink forms a segment of a circle having a flat base plate and equally spaced variable-length fins extending outwardly therefrom. Each plate mates with one side of the water pipe external wall and is secured thereto, preferably with non-heat conductive screws. The outer perimeter of the four mounted finned sections of the heat sink form a circular cross section that can be easily inserted in the cooling cartridge cylindrical shell to form a coaxial annulus for airflow. Means to position the cooling cartridge in its shell and prevent air by-pass are also provided.
An insulating material is affixed between the external flat surfaces of the water flow pipe and a base plate of the heat sink. The insulating material extends around the perimeter of the thermoelectric devices.
The airflow is enhanced by a fan which is mounted at the top of the water flow pipe and within the shell The shell and the water flow pipe define an air passing annulus. The fan is placed so as to draw or induce air upwardly through the air passing annulus.
In the present invention, a housing is detachably mounted onto the flowboard and over the water-cooling cartridge. A spigot is in fluid communication with the outlet of the flowboard and extends outwardly of the housing. Preferably a water filter is in fluid communication with the fluid passageway of the flowboard by a receptacle of the same type used for the subject water cooling cartridge. An electrically operated single ended solenoid valve means is also mounted on the flowboard for controlling fluid flow through the fluid passageway. The valve means is controlled by a fluid dispensing push button (switch) accessibly exposed on an exterior surface of the housing.
A non-intrusive surface thermostat is securely placed directly on the flat conductive top of the water flow pipe to provide an indicative measure of the water temperature within the water flow pipe. The location of the thermostat at the top of the water flow pipe is selected because upwardly flowing cooled water reaches it minimum temperature at this point. The thermostat disconnects power to the thermoelectric devices if surface temperature of the water flow pipe drops below a set point, preferably 35xc2x0 F., to avoid water freezing in the pipe.